How do i add shapes and how do i get a Square?
this forum is happy to help with specifics, but not so much generic (or broad) ranging issues. I am relatively new to Blender and I found the following YouTube tutorial series valuable and these may help you:


Grant Abbitts complete beginners guide to Blender may be a good start (https://www.youtube.com/watch?v=7MRonzqYJgw). I have not done that one, but he has other beginner guides (https://www.youtube.com/playlist?list=PLn3ukorJv4vvWfYmRnGS260JTjhShJFRP) that I have done that are very good.
Blender Guru donut tutorial was interesting and fun and covers a lot of different aspects (https://www.youtube.com/watch?v=TPrnSACiTJ4)
Jayanam (https://www.youtube.com/channel/UCs5J4GVRB8s2P4hE-O0izrg) also does a lot of tutorials.


I was also fortunate enough to do CGBoosts Blender Launch Pad, which really took things from the basic approach, however this is not free.

When doing these tutorials and you get stuck or have a question, this forum will is a very good place to ask and will most likely resolve your questions.